The present invention relates to content delivery systems and methods. More particularly, the present invention relates to systems and methods for reducing the power requirements and cost for delivering content over multicast channels, such as Radio Frequency (RF) spectrum. In some embodiments, this content delivery may provide content on a one-to-many (multicast) platform whereby a central broadcaster transmits data to a plurality of receiver devices. The receiver devices may, in some embodiments, be configured to postpone processing of the content in order to minimize processor requirements. This method enables the receiver devices to maintain a lower overall cost. Furthermore, existing non-receiver-enabled devices, e.g., a remote controller, may be readily enhanced to enable it to receive content via transmission with minimal increase in cost, since the major components may also be used, e.g., during less active periods, to perform tasks associated with the receipt and processing of the transmitted content. Further, devices may be enabled to selectively shut down the receiver until an awaited transmission is being sent, thereby reducing power requirements on the receiver devices. This enables receivers to have smaller battery supplies, enhanced battery life, reduced cost and a better user experience.
As is well known by those skilled in the art, modern digital data communication networks may require the delivery of frames or packets of data (datagrams) from a source endpoint to one or more destination endpoints. Additionally, digital data may instead be streamed. A unicast transfer is the delivery of datagrams, or streamed data transmission between one source endpoint and one destination endpoint. A multicast transfer is the delivery of datagrams between one source endpoint and a subset of possible destination endpoints. The method of transfer depends upon the underlying physical medium used to accomplish data transfer. Physical media used to deliver datagrams include, but are not limited to, short-range unlicensed wireless, long-range unlicensed and licensed wireless, satellite, optical fiber, cable, hybrid fiber/cable and direct point-to-point wiring, among others. Certain media are, by their inherent nature, more suited towards unicast or multicast transfers. In a wireless environment, many endpoints may be within the same radio-frequency (RF) signal coverage, especially in the case of centralized, high-powered transmissions such as radio, satellite, and television.
In particular circumstances the use of a multicast delivery platform may have distinct advantages over unicast delivery. These advantages usually include overcoming financial constraints, and availability constraints.
Availability constraints are most easily exemplified in the context of developing countries, where the infrastructure for a unicast (cellular) network is simply lacking. For example, in many parts of India there is a lack of cellular networks. Delivery of content by cable is likewise unavailable in many cases. Often a single video feed will service an entire village or set of villages. However, while unicast delivery of data is unavailable, there is often radio broadcast coverage in these under-developed regions. The reasons for this are numerous: radio technology is older, and established infrastructures are existent; cost of broadcast on a radio tower is relatively inexpensive; and each radio transmitter covers a very wide area. Further, even if a region isn't serviced by radio transmissions, the cost of installing this kind of an infrastructure is typically within practical reach, as opposed to cellular networks which require large capital investment. Moreover, even in regions that have an established cellular network, access to this network may be prohibitively costly for a large portion of the population.
Thus, if content is distributed via a multicast system, such as using radio frequency (RF) signals, individuals in such areas may gain access to a great deal more information and media content than is currently available. In the India example, this may be utilized to meet particular cultural desires, such as sports (i.e., soccer and cricket) content.
While availability constraints are most easily seen in developing areas where alternative content delivery systems are nonexistent, or too costly for much of the population, other locations and scenarios exist where multicast transmission of content may be preferred due to availability constraints. One such scenario may include a disaster zone where other content delivery systems are either down, or are saturated beyond their ability to properly work. During an emergency, the load on a cellular network increases dramatically. Even if the cellular network is unaffected by the emergency itself, the additional load often results in an overload of the system, wherein many users are unable to access the network resources. Such a strategy is utilized, maliciously, in denial-of-service attacks. Thus, reliable delivery of content through multicast transmission may be particularly useful in emergency situations.
In a similar vein, particular areas of the world have large concentrations of people. Ironically, these areas have the most developed unicast infrastructures for unicast delivery; however, technological limitations, and the sheer density of persons may saturate local networks. An example of this is in New York City, where the density of 3G enabled mobile devices has the propensity to saturate the network and limit cellular connectivity. Again, in such situations, content delivery by multicast may be particularly beneficial as it avoids already saturated unicast networks.
As important as availability constraints, there are financial constraints which may be overcome by using multicast networks for content delivery as well. The financial benefits of multicast are pronounced when common content is being delivered to a large number of receiver devices. This is because, in unicast delivery, network capacity is consumed for each endpoint, even if all endpoints are receiving the same content. Thus, to unicast a video clip to, say, a million users in a metro area requires one million transmissions of the content. In multicast, by comparison, transmission costs are reduced because each piece of content requires only a single transmission. Thus, for the above example, a single transmission of the video clip is sufficient to provide the content to all one million users.
An additional financial constraint is the cost of network connection electronics. Embedding a transceiver (like a 3G cellular modem) into a device is much more costly than embedding a simple receive-only device like an FM data receiver. The savings result both from the absence of transmit circuitry (and the lower power requirements of receivers vs. transmitters), as well as the complexity of the protocols involved in supporting two-way devices on a mobile network. Also, network infrastructure support for two-way data services is inherently more costly than for one-way multicast receiver devices, where both upstream and downstream capacity must be provisioned, and where network infrastructure must be densely deployed so that relatively low-power endpoints can successfully transmit data back to base station locations.
The impact of financial constraints to content delivery may be easily explained through e-reader (e-book) examples. E-readers, such as Amazon's Kindle® and Barnes & Noble's Nook®, are mobile electronic devices which receive and display written content. E-readers are designed to replace paper bound books, newspapers and magazines. In order to offer an effective alternative to traditional printed books and periodicals, e-reader devices must have prolonged battery life, similar weight, convenience, and comparable media costs as compared to printed media. Amazon's Kindle® is currently the leader in e-reader sales and usage. Part of Amazon's success with their e-reader is that the user pays for the device and for content, the wireless plan and back-end costs are managed by Amazon without further cost, or inconvenience, to the user. Thus, the user is not required to pay for or manage a wireless service plan for the device. This is problematic for the distributor, however, since they must manage and pay for the content delivery via the cellular network. While the burden for the delivery costs may be somewhat shifted to the user, content costs must remain “reasonable” in order to compete with traditional print media.
In the case of Amazon's Kindle®, this is mitigated by delivering small sized files to the e-reader device. In general, text-based content is typically less than a megabyte. Magazines and newspaper articles are purposefully ‘stripped’ of images and graphics to prevent content sizes from growing beyond a couple megabytes in size. However, to address user demand for full ‘rich’ versions of content, as well as emerging, even richer versions of content, there is a need to deliver much larger sized content. For example, a typical magazine, with photos intact, can easily reach tens of megabytes in size; a Sunday local newspaper with all advertising supplements may reach over one hundred megabytes in size. The cellular network data delivery costs for content in these size ranges far exceeds the prices that subscribers are willing to pay for the content. Thus, truly “rich” content becomes financially prohibitive to deliver on these devices without shifting wireless plan charges to the user. This is where multicast delivery again provides companies with a competitive advantage by enabling the transmission of “rich” content to a large number of e-reader devices for virtually the same cost as a single transmission. Between financial restraints, and availability constraints, a number of scenarios emerge where multicast may be of particular benefit. These include 1) entertainment content such as sports, music and video segments; 2) digital signs; 3) emergency services; 4) advertisements/schedules for busses/trains; 5) saturated 3G markets; 6) developing countries; 7) brand displays 8) E-readers; and 9) software or database updates for consumer/commercial electronics devices.
In addition to the strong benefits for using multicast to deliver content in particular situations, there is also very little cost associated with developing devices capable of receiving multicast signals over radio frequencies (RF). First, FM receivers are very low cost devices, typically costing no more than one dollar. Second, many devices that already provide FM radio reception and contain the hardware components necessary to receive multicast transmissions. Third, many products contain the hardware necessary to receive FM transmission even though they do not provide FM radio interfaces to users; this is because many combo chipsets designed today include a RF receiver as part of the chip design. These combo chips often include a digital FM filter, an analog to digital (A/D) converter, and a digital signal processor (DSP).
This is the case because chip sizes with or without a small RF receiver typically remain the same; however the circuitry is constantly being reduced in size for power and processing benefits. Thus, there is typically an excess of available room on a typical chip for additional circuitry. The cost to include frequency modulated (FM) radio tuner circuitry on these chips becomes minimal for the chip manufacturers. In fact, the cost of including the FM circuitry on the chip is often substantially lower than generating multiple chip types. A manufacturer packs as much functionality on a combo chip as possible to reduce manufacturing costs and allows the purchaser to use whichever function it desires in their device. Thus, many combo chips include a FM tuner circuit in case a purchaser of the chip desires its functionality. Thus, many devices which do not currently have FM receiver functionality actually include the required hardware to enable the receipt of these signals. In many cases, minor firmware changes are all that is necessary to enable current devices to become capable of receiving radio multicasts.
In view of the foregoing, systems and methods for reducing power and cost for the delivery of content over multicast channels, such as radio frequency spectrum, are disclosed. The present invention provides methods and systems for reducing the need for additional hardware components in receiver devices, as well as minimizing power requirements for multicast receiver devices. Such a system may be utilized to enable a wider range of devices to be connected to external data, and further may remove logistic and financial hurdles to the sale and operation of wirelessly connected consumer devices.